Advances in molecular biology have seen a dramatic increase in the use and need of high capacity assays in testing and analyzing biological substrates or reactions. Existing technology utilizes the binding of molecules contained within a biologically reactive sample fluid, known as a target molecule, onto molecules contained within biologically reactive sites, known as probe molecules. Binding commonly occurs on an apparatus referred to as a biochip, which includes one or more ordered microscopic arrays of biologically reactive sites immobilized on the surface of a substrate, commonly glass. A biologically reactive site can be created by dispensing a small volume of a fluid containing a biological reagent onto a discrete location on the surface of a substrate. Previous assays were originally developed in research laboratories and performed by highly skilled individuals. Adapting these procedures to clinical uses, such as diagnostics, forensics and other applications, has produced the need for equipment and methods that allow less-skilled operators to effectively perform the assays under higher capacity, less stringent assay conditions.
Biochips are advantageously used to perform biological reactions on their surface, however, most existing apparatus are difficult to handle during such common practices as flushing the reaction site, often resulting in cross-contamination of reaction sites. A biochip with two or more assays is preferably flushed with a fluid prior to removal of its various layers in order to prevent cross-contamination between reaction sites. The fluid is typically pushed out by pipetting the appropriate volume of flush fluid into one port of the reaction chamber, causing fluid to exit a second port of the reaction chamber located separate from the first. The flushing process is messy in that the exiting fluid spills over the edge of the slide and can itself lead to cross-contamination if the exiting fluid enters the port of an adjacent reaction chamber. It is desired to remove the exiting fluid as quickly and efficiently as possible to reduce the possibility of cross-contamination.
Additionally, removal of the various layers requires some force which must be resisted by holding the biochip as a whole. The biochip is difficult to hold by hand as it often has sharp edges and can be an awkward shape and size. Bobbling of the slide during removal can also result in cross-contamination or the dropping or damaging of the biochip itself.